エクスクルーシブ
Lifelines <mv-lifelines>
1 つだけを選ぶ難しい選択（プラン、配送方法、ノートパソコンの構成、保険の等級、インスタンスのサイズ）のための判断補助です。それぞれが使用回数の限られたライフラインで、使った分が目に見えて減ります。
文化的リファレンス
Who Wants to Be a Millionaire?、デヴィッド・ブリッグス、マイク・ホワイトヒル & スティーヴン・ナイト（ITV）（1998年、クイズ番組）。行き詰まった挑戦者は、各ライフラインを一度ずつ使えます。1 つは不正解を 2 つ消し、1 つはスタジオの観客の投票結果を見せ、1 つは信頼できる友人に電話をかけます。UI では、同じ 3 つのヘルパーが難しい製品選びを手助けします。合わない選択肢を（理由付きで）脇に置き、似た顧客が何を選んだかを示し、候補リストを同僚に送って投票してもらいます。使ったヘルパーは目に見えて消費済みになり、確信度の表示がそれらをまとめます。
仕組み
難しい 1 つの選択（プラン、配送オプション、ノート PC の構成、保険のランク、インスタンスサイズ）のための意思決定ヘルパーです。それぞれが使用回数の限られたライフラインで、使うと目に見えて消費済みになります。独自のネイティブなラジオやオプションカードをラップするだけで置き換えることはないため、フォームの値、バリデーション、矢印キーはブラウザ標準のままです。「Narrow it down」は、narrow(context) 関数または data-fit のスコアを使い、ユーザーが示したニーズに明らかに合わない選択肢を脇に置きます。除外にはそれぞれ理由が付き、現在の選択が隠されることはなく、最低限の選択肢数が保たれ、「Show them」で脇に置いた選択肢を戻せます（選択も可能なままです）。「What others chose」は、data-share 属性、または統計のオブジェクトや関数をもとに、全体と「people like you」セグメントについて各選択肢に割合付きの分布バーを追加し、最も選ばれた選択肢にマークを付けます。「Ask someone」は、候補リストと現在の選択に任意で投票リンクを加えた編集可能なメッセージを作成し、Web Share API で送信するかコピーします。回答は addVote() で戻り、各選択肢に表示されます。確信度の表示は、現在の選択についての適合度、多数派の傾向、投票を組み合わせて、理由付きの Strong / Moderate / Low のレベルにまとめます。すべてのライフラインはキャンセル可能な mv-lifeline イベントを経由し、その waitUntil(promise) でサーバーから適合度、統計、投票リンクを取得できます。
| カテゴリー | フォーム |
|---|---|
| タイプ | Web Component（<mv-lifelines>） |
| ステータス | 安定版 |
| 同時にインストールされるもの | button, textarea |
| Keywords | exclusive, culture, decision, choice, radio-group, option-cards, plan-picker, pricing, shipping, configurator, recommendation, social-proof, share, web-share, voting, confidence, filter, form |
When to use
- Users stall on a plan, tier or configuration picker and need help ruling out options before they commit
- The app knows the user's needs (team size, deadline, budget) and can explain why an option doesn't fit
- Showing what similar customers picked would reassure a hesitant buyer without pushing a single recommendation
- A purchase is often decided with a colleague or partner, and the shortlist should be easy to send them for a vote
Avoid when
- The choice is between two to five quick, low-stakes settings like view mode or alignment → use Segmented instead
- The options only need to be listed as cards with a price and badge, with no decision help → use Radio instead
- Plans must be compared feature by feature in a full pricing section with a billing toggle → use Pricing instead
インストール
node scripts/add.mjs lifelines --out ./src/marvelousMarvelous UI MCP サーバーを使う AI エージェント：install_components({ slugs: ["lifelines"], target_dir: "<absolute path>/src/marvelous", framework: "react" })。
コピーされるファイル（依存関係を含む）：tokens/tokens.css, core/base.css, components/button/button.css, core/dom.js, core/element.js, components/textarea/textarea.css, components/textarea/char-count.js, core/motion.js, components/lifelines/lifelines.js, components/lifelines/lifelines.css。
使い方
基本となるマークアップです。ここから属性、data-*、CSS 変数でカスタマイズしてください：
<div id="ll-demo" style="width:min(100%,66rem);margin-inline:auto">
<style>
#ll-demo { display:grid; gap:1.25rem; align-content:start }
#ll-demo .ll-layout { display:grid; grid-template-columns:minmax(0,1fr) 16.5rem; gap:1.25rem; align-items:start }
#ll-demo .ll-card { min-width:0; border:1px solid var(--mv-border); border-radius:var(--mv-radius-xl); background:var(--mv-surface); box-shadow:var(--mv-shadow-sm) }
#ll-demo .ll-head { display:flex; align-items:flex-end; justify-content:space-between; gap:.75rem 1.25rem; flex-wrap:wrap; padding:1.125rem 1.25rem 1rem; border-bottom:1px solid var(--mv-border) }
#ll-demo .ll-head h3 { margin:0; font-size:1.0625rem; letter-spacing:-.01em }
#ll-demo .ll-head p { margin:.1875rem 0 0; color:var(--mv-fg-muted); font-size:.8125rem }
#ll-demo .ll-needs { display:flex; align-items:flex-end; gap:.75rem; flex-wrap:wrap }
#ll-demo .ll-need { display:grid; gap:.3125rem; font-size:.75rem; font-weight:500; color:var(--mv-fg-muted) }
#ll-demo .ll-need .mv-select { width:auto; min-width:7.5rem; height:var(--mv-control-sm); font-size:.8125rem }
#ll-demo .ll-need .mv-choice { height:var(--mv-control-sm); align-items:center; font-size:.8125rem }
#ll-demo .ll-body { padding:1.125rem 1.25rem 1.25rem }
#ll-demo .mv-choice-group legend { font-size:.8125rem; color:var(--mv-fg-muted) }
#ll-demo .mv-radio-meta { margin-inline-start:auto; padding-inline-start:.5rem; font-weight:600; font-size:.875rem; white-space:nowrap; font-variant-numeric:tabular-nums }
#ll-demo .mv-radio-meta small { color:var(--mv-fg-muted); font-weight:500; font-size:.75rem }
#ll-demo .ll-side { position:sticky; top:1rem; display:grid; gap:1rem; padding:1.125rem; border:1px solid var(--mv-border); border-radius:var(--mv-radius-xl); background:var(--mv-surface-raised); box-shadow:var(--mv-shadow-sm); font-size:.8125rem }
#ll-demo .ll-side h4 { display:flex; align-items:center; justify-content:space-between; gap:.5rem; margin:0; font-size:.8125rem; font-weight:600 }
#ll-demo .ll-side p { margin:0; color:var(--mv-fg-muted); font-size:.75rem; line-height:1.45 }
#ll-demo .ll-votes { display:grid; gap:.5rem }
#ll-demo .ll-votes .mv-button { justify-content:flex-start; width:100% }
#ll-demo .ll-sep { height:1px; background:var(--mv-border) }
#ll-demo .ll-log { display:grid; gap:.3125rem; margin:0; padding:0; list-style:none; font:.6875rem/1.45 var(--mv-font-mono); color:var(--mv-fg-muted) }
#ll-demo .ll-log li { overflow:hidden; text-overflow:ellipsis; white-space:nowrap }
#ll-demo .ll-log b { color:var(--mv-fg); font-weight:500 }
#ll-demo .ll-ship .ll-body { display:grid; grid-template-columns:minmax(0,15rem) minmax(0,1fr); gap:1.5rem; align-items:start }
#ll-demo .ll-order { display:grid; gap:.625rem; font-size:.8125rem }
#ll-demo .ll-order dl { display:grid; gap:.375rem; margin:0 }
#ll-demo .ll-order dl div { display:flex; justify-content:space-between; gap:.5rem }
#ll-demo .ll-order dt { color:var(--mv-fg-muted) }
#ll-demo .ll-order dd { margin:0; font-variant-numeric:tabular-nums }
#ll-demo .ll-order .ll-by { display:flex; gap:.5rem; align-items:flex-start; padding:.625rem .75rem; border-radius:var(--mv-radius-lg); background:var(--mv-bg-subtle); color:var(--mv-fg-muted); font-size:.75rem; line-height:1.45 }
#ll-demo .ll-order .ll-by b { color:var(--mv-fg); font-weight:600 }
#ll-demo .ll-hint { margin:0; color:var(--mv-fg-muted); font-size:.75rem; text-align:center }
@media (max-width:54rem) {
#ll-demo .ll-layout { grid-template-columns:minmax(0,1fr) }
#ll-demo .ll-side { position:static }
#ll-demo .ll-ship .ll-body { grid-template-columns:minmax(0,1fr) }
}
</style>
<div class="ll-layout">
<!-- Main: choosing a workspace plan, with the app's own narrow() and stats() -->
<section class="ll-card" aria-labelledby="ll-plan-title">
<header class="ll-head">
<div>
<h3 id="ll-plan-title">Choose a plan for Kestrel Studio</h3>
<p>You can switch plans at any time. Prices billed yearly.</p>
</div>
<div class="ll-needs" role="group" aria-label="Your needs">
<label class="ll-need">Team size
<select class="mv-select" id="ll-seats">
<option value="2">1-3 people</option>
<option value="8" selected>4-10 people</option>
<option value="18">11-25 people</option>
<option value="60">26-100 people</option>
</select>
</label>
<label class="ll-need">Storage
<select class="mv-select" id="ll-storage">
<option value="5">5 GB</option>
<option value="50" selected>50 GB</option>
<option value="500">500 GB</option>
</select>
</label>
<span class="ll-need">Security
<label class="mv-choice"><input type="checkbox" role="switch" class="mv-switch" id="ll-sso"> SSO required</label>
</span>
</div>
</header>
<div class="ll-body">
<mv-lifelines id="ll-plan" similar-label="teams of 4-10"
question="Which plan should we get for the design team? We’re 8 people."
share-url="https://app.example.com/plans/vote?options={shortlist}&pick={pick}">
<fieldset class="mv-choice-group" data-layout="grid" style="--mv-choice-min:17rem">
<legend>Plan</legend>
<label class="mv-choice-card">
<input type="radio" class="mv-radio" name="ll-plan" value="starter">
<span class="mv-choice-text"><span class="mv-choice-title">Starter</span><span class="mv-choice-description">Up to 3 seats · 5 GB · Community support</span></span>
<span class="mv-radio-meta">$0</span>
</label>
<label class="mv-choice-card">
<input type="radio" class="mv-radio" name="ll-plan" value="team" checked>
<span class="mv-choice-text"><span class="mv-choice-title">Team</span><span class="mv-choice-description">Up to 25 seats · 100 GB · Shared libraries</span></span>
<span class="mv-radio-meta">$12 <small>/ seat</small></span>
</label>
<label class="mv-choice-card">
<input type="radio" class="mv-radio" name="ll-plan" value="business">
<span class="mv-choice-text"><span class="mv-choice-title">Business</span><span class="mv-choice-description">Unlimited seats · 1 TB · SSO and audit log</span></span>
<span class="mv-radio-meta">$24 <small>/ seat</small></span>
</label>
<label class="mv-choice-card">
<input type="radio" class="mv-radio" name="ll-plan" value="enterprise">
<span class="mv-choice-text"><span class="mv-choice-title">Enterprise</span><span class="mv-choice-description">From 50 seats · SSO and SCIM · 99.99% SLA</span></span>
<span class="mv-radio-meta">Custom</span>
</label>
</fieldset>
</mv-lifelines>
</div>
</section>
<aside class="ll-side" aria-label="Demo controls">
<h4>Replies you received <span class="mv-badge" data-variant="secondary" data-shape="pill" id="ll-count">0 votes</span></h4>
<p>Your app collects answers from the shared link and feeds each one back with <code>addVote()</code>.</p>
<div class="ll-votes">
<button class="mv-button" data-variant="outline" data-size="sm" type="button" data-vote="team" data-from="Priya Raman" data-note="Team covers us, keep the budget for fonts.">Priya picks Team</button>
<button class="mv-button" data-variant="outline" data-size="sm" type="button" data-vote="business" data-from="Marcus Olsen" data-note="We’ll want SSO once the agency joins.">Marcus picks Business</button>
<button class="mv-button" data-variant="outline" data-size="sm" type="button" data-vote="team" data-from="Aiko Tanaka">Aiko picks Team</button>
</div>
<div class="ll-sep"></div>
<button class="mv-button" data-variant="secondary" data-size="sm" type="button" id="ll-reset">Give lifelines back</button>
<div class="ll-sep"></div>
<h4>Events</h4>
<ol class="ll-log" id="ll-log"><li>-</li></ol>
<span class="mv-sr-only" role="status" id="ll-status"></span>
</aside>
</div>
<!-- Variant: declarative data only (data-fit, data-share), two lifelines, no confidence readout -->
<section class="ll-card ll-ship" aria-labelledby="ll-ship-title">
<header class="ll-head">
<div>
<h3 id="ll-ship-title">Shipping</h3>
<p>Order #48213 · 2 items · to Chicago, IL 60614</p>
</div>
</header>
<div class="ll-body">
<div class="ll-order">
<dl>
<div><dt>Trail runner, size 9</dt><dd>$128.00</dd></div>
<div><dt>Merino socks, 2 pairs</dt><dd>$24.00</dd></div>
</dl>
<p class="ll-by"><span>You said it’s a gift for <b>Friday, October 2</b>. Options that won’t arrive in time can be set aside.</span></p>
</div>
<mv-lifelines lifelines="narrow, poll" threshold="0.7" show-confidence="false" similar-label="shoppers in Chicago" poll-note="Orders shipped to Illinois in the last 30 days." label="Not sure which one?">
<fieldset class="mv-choice-group">
<legend>Delivery</legend>
<label class="mv-choice-card" data-fit="0" data-fit-reason="Arrives Oct 5-7, after Friday" data-share="38" data-share-similar="22">
<input type="radio" class="mv-radio" name="ll-ship" value="economy">
<span class="mv-choice-text"><span class="mv-choice-title">Economy</span><span class="mv-choice-description">6-8 business days</span></span>
<span class="mv-radio-meta">Free</span>
</label>
<label class="mv-choice-card" data-fit="0.55" data-fit-reason="Arrives Sep 30 to Oct 2, cutting it close" data-share="41" data-share-similar="44">
<input type="radio" class="mv-radio" name="ll-ship" value="standard" checked>
<span class="mv-choice-text"><span class="mv-choice-title">Standard</span><span class="mv-choice-description">3-5 business days</span></span>
<span class="mv-radio-meta">$6.99</span>
</label>
<label class="mv-choice-card" data-fit="1" data-fit-reason="Arrives Monday, Sep 28" data-share="16" data-share-similar="27">
<input type="radio" class="mv-radio" name="ll-ship" value="express">
<span class="mv-choice-text"><span class="mv-choice-title">Express</span><span class="mv-choice-description">2 business days, tracked</span></span>
<span class="mv-radio-meta">$14.99</span>
</label>
<label class="mv-choice-card" data-fit="0.85" data-fit-reason="Ready Thursday, Oct 1 at Lakeview Market" data-share="5" data-share-similar="7">
<input type="radio" class="mv-radio" name="ll-ship" value="pickup">
<span class="mv-choice-text"><span class="mv-choice-title">Pickup point</span><span class="mv-choice-description">Collect from a locker near you</span></span>
<span class="mv-radio-meta">$3.99</span>
</label>
</fieldset>
</mv-lifelines>
</div>
</section>
<p class="ll-hint">Each lifeline works once · “Narrow it down” was already used on the plan picker · change your needs to re-check the set-aside plans</p>
<script type="module">
await customElements.whenDefined("mv-lifelines");
const $ = (id) => document.getElementById(id);
const ll = $("ll-plan");
const PLANS = {
starter: { seats: 3, storage: 5, sso: false, min: 1 },
team: { seats: 25, storage: 100, sso: false, min: 1 },
business: { seats: Infinity, storage: 1000, sso: true, min: 1 },
enterprise: { seats: Infinity, storage: 5000, sso: true, min: 50 },
};
const readNeeds = () => ({ seats: Number($("ll-seats").value), storage: Number($("ll-storage").value), sso: $("ll-sso").checked });
const gb = (n) => (n >= 1000 ? `${n / 1000} TB` : `${n} GB`);
// The app's own fit logic: 0..1 per option, with the reason shown to the user.
ll.needs = readNeeds();
ll.narrow = ({ needs, options }) => options.map(({ value }) => {
const p = PLANS[value];
if (p.seats < needs.seats) return { value, fit: 0.1, reason: `Up to ${p.seats} seats, you need ${needs.seats}` };
if (p.min > needs.seats) return { value, fit: 0.2, reason: `Starts at ${p.min} seats, you need ${needs.seats}` };
if (p.storage < needs.storage) return { value, fit: 0.15, reason: `${gb(p.storage)} of storage, you need ${gb(needs.storage)}` };
if (needs.sso && !p.sso) return { value, fit: 0.15, reason: "No single sign-on" };
if (!needs.sso && p.sso) return { value, fit: 0.65, reason: "Fits, but you’d pay for SSO you don’t need" };
return { value, fit: 0.92, reason: `Room for ${Number.isFinite(p.seats) ? p.seats : "unlimited"} seats and ${gb(p.storage)}` };
});
// What others chose: overall and for teams of the same size.
const SEGMENTS = {
2: ["teams of 1-3", { starter: 71, team: 22, business: 6, enterprise: 1 }],
8: ["teams of 4-10", { starter: 9, team: 58, business: 29, enterprise: 4 }],
18: ["teams of 11-25", { starter: 2, team: 47, business: 43, enterprise: 8 }],
60: ["teams of 26-100", { starter: 1, team: 12, business: 52, enterprise: 35 }],
};
ll.stats = ({ needs }) => {
const [similarLabel, similar] = SEGMENTS[needs.seats];
return {
everyone: { starter: 41, team: 33, business: 19, enterprise: 7 },
similar, similarLabel,
note: "Based on 12,480 workspaces created in the last 90 days.",
};
};
const log = $("ll-log");
const push = (html) => {
if (log.firstElementChild?.textContent === "-") log.replaceChildren();
const li = document.createElement("li");
const [name, rest] = html;
li.append(Object.assign(document.createElement("b"), { textContent: name }), ` ${rest}`);
log.prepend(li);
while (log.children.length > 5) log.lastElementChild.remove();
};
ll.addEventListener("mv-lifeline", (e) => push(["mv-lifeline", `${e.detail.lifeline}${e.detail.refresh ? " (refresh)" : ""}`]));
ll.addEventListener("mv-lifeline-result", (e) => push(["result", `${e.detail.lifeline} · ${e.detail.confidence?.level ?? "no pick"}`]));
ll.addEventListener("mv-change", (e) => push(["mv-change", `${e.detail.value} · ${e.detail.confidence?.level ?? "-"}`]));
ll.addEventListener("mv-share", (e) => push(["mv-share", e.detail.method]));
ll.addEventListener("mv-vote", (e) => {
push(["mv-vote", `${e.detail.vote.from} → ${e.detail.vote.value}`]);
const n = e.detail.votes.length;
$("ll-count").textContent = `${n} vote${n === 1 ? "" : "s"}`;
});
// Start with one lifeline already spent, so the mechanic is visible.
ll.use("narrow");
for (const id of ["ll-seats", "ll-storage", "ll-sso"]) {
$(id).addEventListener("change", () => {
ll.needs = readNeeds();
ll.refresh();
});
}
document.querySelectorAll("#ll-demo [data-vote]").forEach((btn) => {
btn.addEventListener("click", () => {
ll.addVote({ value: btn.dataset.vote, from: btn.dataset.from, note: btn.dataset.note });
btn.disabled = true;
});
});
$("ll-reset").addEventListener("click", async () => {
await ll.reset();
document.querySelectorAll("#ll-demo [data-vote]").forEach((b) => { b.disabled = false; });
$("ll-count").textContent = "0 votes";
$("ll-status").textContent = "All lifelines are available again.";
});
</script>
</div>API
Attributes
| Name | タイプ | Default | Description |
|---|---|---|---|
lifelines | comma list of narrow | poll | ask | narrow, poll, ask | Which lifelines are offered, in toolbar order. |
uses | number | "unlimited" | "narrow:1, poll:2, ask:unlimited" | 1 | How many times each lifeline can be used: one number for all, or per lifeline ("*" sets the default for the others). Up to five uses show as dots, more as a count. |
threshold | number (0..1 or %) | 0.5 | Fit below which “Narrow it down” sets an option aside. Changing it re-runs a narrowing already done, without spending a use. |
keep | number | 2 | Minimum number of options left visible after narrowing. The best-fitting of the would-be removals are kept to reach it. The checked option is never set aside; if it fits poorly it is flagged “Might not fit” instead. |
name | string | Name of the radio group to manage when the element contains several. Defaults to the name of the first radio inside. | |
label | string | Need a hand deciding? | Visible label of the lifelines toolbar (also its accessible name). An empty value hides it. |
similar-label | string | people like you | Name of the “people like you” segment, written lowercase to read inside sentences (“Chosen by 58% of teams of 4-10”). It is capitalized where it starts a label. A stats object's similarLabel wins. |
poll-note | string | Where the statistics come from, shown in the “What others chose” note (“Orders shipped to Illinois in the last 30 days.”). A stats object's note wins. | |
share-url | URL template | Link added to the “Ask someone” message, for example your vote page. {shortlist} (comma-separated values still visible) and {pick} are replaced, URI-encoded. A url resolved by waitUntil wins. | |
question | string | Could you help me decide? Here are the options I’m weighing: | First line of the “Ask someone” message and title of the Web Share payload. |
show-confidence | "true" | "false" | true | "false" hides the confidence readout (the confidence property still works). |
data-fit / data-fit-reason | number (0..1 or %) / string | On an option (its label, a [data-option] wrapper or the radio): declarative fit score and the reason shown to the user. Used when narrow() is not set or returns nothing for that option. | |
data-share / data-share-similar | number | On an option: share of everyone and of the “people like you” segment who chose it. Percentages, fractions (sum ≤ 1) or raw counts (sum above 100) are all normalized to percentages. | |
data-option / data-label / data-summary | attribute / string / string | On an option: data-option marks the wrapper when it isn't the radio's <label>; data-label and data-summary override the name and summary used in announcements and in the “Ask someone” message (defaults: .mv-choice-title, then .mv-choice-description · .mv-radio-meta). | |
data-lifelines="toolbar | notes | readout" | attribute | Place on your own empty containers to choose where the toolbar, the notes and the readout go. By default the toolbar and notes are prepended and the readout appended. | |
data-lifeline-fit / data-lifeline-top / data-lifelines-hidden | set by the component | On each option: fit | poor | out after narrowing, data-lifeline-top on the most chosen option, data-lifelines-hidden while an option is set aside and hidden (styleable). |
Properties
| Name | タイプ | Description |
|---|---|---|
narrow | (context) => fits | Promise<fits> | Your fit logic. context: { needs, value, options: [{ value, label, summary, element, data }], setAside }. Return [{ value, fit, reason }] or { [value]: fit | { fit, reason } }, with fit in 0..1 (or a percentage). |
stats | object | (context) => object | Promise<object> | What others chose: { everyone: { [value]: share }, similar?: { [value]: share }, similarLabel?, everyoneLabel?, note? }, a flat { [value]: share } map, or [{ value, share, similar }]. Setting it after the lifeline was used updates the bars in place. |
needs | any | The user's stated needs, passed to narrow() and stats() as context.needs. Call refresh() after changing it. |
value | string | Value of the checked radio. Setting it checks the matching radio (showing it again if it was set aside) without emitting mv-change. |
confidence | { value, level, label, pick, signals } | null | Read-only. value 0..1 (null without signals), level "high" (≥ 0.7) | "medium" (≥ 0.4) | "low", signals: [{ kind: "fit" | "crowd" | "votes", value, tone: "good" | "neutral" | "bad", text }]. Weighted mean: fit 0.5, crowd 0.25 (the pick's share relative to the most chosen), votes 0.25. |
votes | [{ value, from, note, at }] | Answers received through addVote() (read-only copy). |
setAside | string[] | Values currently set aside by “Narrow it down” (read-only). |
strings | Partial<Record<string, string>> | Overrides for every visible text and announcement (toolbarLabel, narrow, poll, ask, used, narrowTitle, narrowText, showAside, hideAside, tagOut, tagPoor, pollTitle, everyone, similar, mostChosen, mostChosenBy, askTitle, askText, share, copy, copied, question, askLeaning, askReply, askLink, answers, confidenceFor, levelHigh, levelMedium, levelLow, signalFit, signalCrowd, signalVotes, announce*…). English defaults. |
Methods
| Name | Description |
|---|---|
use(name) | Runs a lifeline ("narrow" | "poll" | "ask") as if its button was pressed. Resolves to true when it ran; for ask, when its panel opened. A lifeline with nothing to show (no data) is not spent. |
usesLeft(name) | Remaining uses of a lifeline (Infinity when unlimited). |
refresh() | Re-runs the lifelines already used (narrow and poll) against the current needs and data, without spending a use. mv-lifeline fires with refresh: true. |
showAll(force?) | Shows (true) or hides (false) the set-aside options; toggles without argument. Resolves to the new state. |
addVote({ value, from?, note? }) | Feeds back an answer from someone you asked. A second vote from the same person replaces the first. Returns false for an unknown value. |
clearVotes() | Removes every vote. |
reset() | Gives every lifeline back and clears narrowing, statistics and votes; set-aside options come back. |
openAsk() / closeAsk() | Opens or closes the “Ask someone” panel. |
Events
| Name | Description |
|---|---|
mv-lifeline | Cancelable, before a lifeline runs (for ask: when its panel opens for a new use). detail: { lifeline, refresh, usesLeft, context, waitUntil(promise) }. preventDefault() vetoes it (nothing is spent). Promises passed to waitUntil show a busy state; the last non-null value they resolve to is used as the data: fits for narrow, stats for poll, { text?, url? } for ask. A rejection spends nothing and emits mv-lifeline-error. |
mv-lifeline-result | A lifeline ran. detail: { lifeline, refresh, result, confidence }. result: { setAside: [{ value, label, fit, reason }], fits } for narrow, { everyone, similar, top } for poll, { method, text, url } for ask. |
mv-lifeline-error | A waitUntil promise, narrow() or stats() threw. detail: { lifeline, error }. |
mv-change | The user picked another option. detail: { value, label, confidence }. The native change event still bubbles from the radio. |
mv-share | The “Ask someone” message was shared or copied. detail: { method: "share" | "copy", text, url }. The first one of a use spends it. |
mv-vote | addVote() recorded an answer. detail: { vote, votes, confidence }. |
Content structure
| Name | Description |
|---|---|
(content) | Your radio group: a <fieldset> of .mv-choice-card or .mv-choice labels, or any markup with native radios. Per-option results go into [data-lifelines-slot] if present, else .mv-choice-text, else the option wrapper. |
CSS classes
| Name | Description |
|---|---|
mv-lifelines-toolbar | Labelled group holding -toolbar-label and .mv-lifelines-buttons. |
mv-lifelines-lifeline | A lifeline button: -lifeline-icon, -lifeline-label, .mv-lifelines-uses (dots, count or “Used”). data-lifeline, data-state="available | busy | used", data-spent during the spend pulse. |
mv-lifelines-note / mv-lifelines-ask | What each lifeline found, under the toolbar: -note-icon, -note-title, -note-text, -note-list, .mv-lifelines-legend. The ask panel adds .mv-lifelines-message (textarea), -ask-actions and .mv-lifelines-answers. |
mv-lifelines-aside | Per-option results (aria-hidden, linked to the radio with aria-describedby): .mv-lifelines-tag, .mv-lifelines-reason[data-kind], .mv-lifelines-poll > .mv-lifelines-row[data-segment] (-row-label, .mv-lifelines-meter, -row-value), .mv-lifelines-votes. |
mv-lifelines-readout | Confidence readout, data-level="high | medium | low | none": -readout-title, .mv-lifelines-level, .mv-lifelines-gauge, .mv-lifelines-signals > li[data-tone]. |
CSS variables
| Name | Default | Description |
|---|---|---|
--mv-lifelines-accent | var(--mv-accent) | Lifeline icons, remaining-use dots, spend pulse and the “Moderate” level. |
--mv-lifelines-everyone | 38% fg mixed into bg | Bar color of the “everyone” segment. |
--mv-lifelines-similar | var(--mv-lifelines-accent) | Bar color of the “people like you” segment. |
--mv-lifelines-good | var(--mv-success) | Good-fit marks and the “Strong” level. |
--mv-lifelines-bad | var(--mv-warning) | Poor-fit marks and the “Low” level. |
Accessibility
The native radios are never replaced: the group keeps its <fieldset>/<legend>, arrow keys, required validation and form value. Lifelines are real <button>s in a group labelled by the visible toolbar label. Each button's name includes its state (“Narrow it down, 1 use left” / “, used” / “, working” with aria-busy). A spent lifeline keeps focus and gets aria-disabled="true"; pressing it announces that it was already used. The “Ask someone” button stays operable to reopen its panel, with aria-expanded and aria-controls. Results are announced once in a polite live region (“Set aside Starter and Enterprise. 2 options left. Confidence in Team: strong.”; “Most chosen by teams of 4-10: Team, 58%.”; “Priya Raman picked Team.”); selecting options never chatters. Per-option results are visible text, bars included (every bar has its percentage written next to it). They are aria-hidden inside the label so they don't lengthen the radio's name, and linked with aria-describedby, so a screen reader hears “Team, radio button, 2 of 4. Most chosen by teams of 4-10. Good fit: Room for 25 seats and 100 GB. Everyone 33%, teams of 4-10 58%”. Set-aside options leave the layout and the arrow-key cycle; the “Show them” toggle (aria-pressed, aria-controls pointing at the hidden options) brings them back selectable, marked “Set aside” with their reason, and the checked option is never hidden. The ask panel is a labelled region with a real <label> on its editable message; focus moves into it on open, and Escape or Close returns focus to the button. Share and copy results are announced, and if copying fails the message is selected for manual copy. Fit, crowd and confidence tones always come with an icon and words, never color alone. Reduced motion (OS or data-motion="reduce"): no FLIP, no bar growth, no spend pulse or busy blink. Forced colors: borders, use dots and bars fall back to system colors.